Stoker



G. A. KoHouT S TOKER Filed Ocft. 7, 1943 5 Sheets-Sheet l fraz/@72% 05g@JYOOQZ" Z5 Sheets-Sheet 2 STOKER G. A. KQHOUT Filed oct; 7, 1945 April16, 1946;

April 16, 1946. A. KoHouT S'TOKER Filed oct. 7, 1945 5 Sheets-Sheet 5Patented Apr. 16, 1946 g I UNITED ,A Nsfr.\.-'rr-:,s PATENT ,ol-*Fiche yI 2.398,4?.1` e i e i STOKER l Georgeglohout;f lhicagmjlll.4jApplieatiqnotobei 7, 1943, serialNo. `505,288 1 l `7 elaine.'(0151104104)l i The present invention relates to stokers and isparticularly concerned with the provision of a stoker unit which isportable and which is adapted to be applied to Aany existing furnace bythe simpleexpedient of providing an openinga short distance above thegrate over the re and moving the stoker unit into position with itsdischarge end extending into the furnace opening.

It is the principal purpose of this inventionto provide a Stoker of thegeneral character above described by which ordinary coal varying insize, wet or dry, may be advanced from a hopper to an air blast duct andforced by an air blast through the duct into the furnace and spread insuch fashion as to substantially uniformly cover the grate, I am awareof course that many stokers have been made wherein the fuel is forcedinto the furnace by an air or steam blast and distributed by the forceof the blast within the furnace. My prior Patents Nos. 2,178,360 and2,257,693 illustrate lone type ofstoker of this character. The stoker ofthe present invention is particularly advantageous in handling wet coal.Furthermore, it has the advantage, that if the coal contains particlesthat are too large it will separate these large particles and returnthem to the hopper until they become broken up to a size that will behandled readily by the air blast.

The invention contemplates a portable stoker ofthe character describedwherein the air blast' conduit through which the coal is advanced intothe furnace may be heated by the furnace gases to any desired degreewhereby to facilitate `the handling of wet coal andto prevent it fromsticking in the air blast conduit. The invention contemplates alsodeecting devices associated with the air blast conduit whereby tocontrol the spread of the fuel over the furnace grate and prevent theair blast `from blowing the fuel over the bridge wall in the furnace.

More. particularly it is a purpose of the present invention to provide aportable stoker with a variable feed that is capable of being applied toany existing furnace installation and that willr feed the coal reliablythrough a wide range 'of rates regardless of whether the coal is dry orwet.

The features and-advantages of the invention will appear more fully asthe description proceeds 4, in connection with the accompanying drawingswherein a preferred form of the invention is shown. It should beunderstood however that the drawings and description are illustrativeonly and are not to be taken as limiting the invention except insofar asit is limited by the claims.

In the drawings: I

Figure 1 is a longitudinal sectional view taken through a furnaceshowing my-irnprovedstoker connected thereto for supplying fuel tothecoinbustion chamber ofthe furnace;` l

Figure` 2 'is a" longitudinal sectional view taken through the Stokerand showing itin feedingposition; i W l Figure 3 is a planVsectiohalview taken'on the line 343 of Figure 2; Y' f i Figure 4 is aplan sectional View taken on the line 4-4 of Figure 2; I v l Figure 5 isa view in side elevation of the fuel feeding duct casting fof theStoker, this view being taken to s'how the side opposite that shown inFigure 2;`AV Y 1 Figure 6-is a sectional 6-6 of FigureZ; and .i

Figure'lis anenlarged sectional 4Vview taken on the line 1-1 ofFigureReferring now indetail-to the drawings, the furnace shown.diagrammatically in Figure 1 has a front'wall :I 0, a bridge wall IIanda combustion chamber I2in whichfa grate I3 is mounted. i The frontwall yis shown as provided with an opening view taken von the line I4`below the level of the grate-Which is closed by a doorA I5. The frontwall also has an opening I6 above the grater and substantially on thelevel therewith, this opening being closed by a door II.y `.The `openingI4 is ofcourse to permit access beneath the grate totheV ash chamber,"While the opening I6 permits direct accessto the top of theV grate forcleaning it. The 'furnace also is `provided with a third opening I8above the opening I6, which opening is the fuel feed opening throughwhich coal is blown and spread over the grate I3. i My inventioncomprises a stoker 2li including a hopper 2I that is tilted-at an angleof substan-` tially degrees tothe horizontal. The hopper has side walls22 and 23 that converge forwardly and a bottom wall. 24 on vwhich afeedscrew 25 is located. The back endof the hopper is closed by a plate 126and the side and end wall extensions 21, 28 and29 are provided toincrease the capacity ofthe hopper itself. 1M. I

A .tubular fuel feeding'casting 30 extends into the-opening I-8. #Thiscasting -is provided with a small hopper 3| that extends from an opening32 in the top of the casting to an opening 33 in the bottom wall 24 ofithe hopper near its upper end. The'opening 33 iscovered by a perforatedpart .34l of ra feed screw housing, I I5, the perforations 35 in thispart being of such a size as to pass coal up to the sizes it isV desiredto have enter the furnacethrough the casting 30.` 1 The vcasting301consists of an :upper hollow portion36 and up of a rear extension 40of the bottom wall 24 of the hopper. vThis plate extension 46 hasbrackets 4l thereon which extend downwardly and provide means formounting the plate on a shaft `42 on which is journaled two supportingwheels 43 and 44. The plate 46 supports a motor 45 which may be variablein speed or which may be connected by variable speed mechanism indicatedgenerally at 46 and 41 to a shaft 48 on the feed screw 25. Any suitablevariable speed mechanism is sufficient for connecting the shaft 48 tothe motor 45^so as to give a wide range of speeds to thefeed screw.

. The plate 48 is connected by two channel irons 49 to a front post -50which is telescoped with another post I that is mounted on a small wheel52. A `clamp '53 is provided on the post 5I so as to determine theheight of the post 50. It will be evident that by releasing the clampand setting it lower or higher on the post 5I the post 50 and the partssupported thereby can be Achanged in elevation. The post 50 carries aplate 54 at the top thereof which supports the casting 39, the castinghavingsuitable flanges 55 bolted to the plate 54. The plate 54 desirablyis cut out to receive a pipe 56 that extends downwardly from' thecasting. The pipe 56 has swiveled on its lower end a hollow T 51 and theT 51 carries a pipeY extension 58 and an enlarged discharge bell 59. Anopening 56a is cut inthe wall of the pipe 56. The lower end of the pipe56 is closed by a 'plug 56h.

. The channel irons *49 serve to support a. plate 68 which `is the baseof a fan 6I The fan 6| preferably is of the centrifugal type and has itsdischargeend' 62 extending upwardly into the rear end of ltheV upperduct 36 of the casting 3U. The inletV of .the fan is in the side thereoffacing the bell V'59 andthe bell kis held in radjusted position withrespect tothe inlet 63 by an adjustable stop screw64 that is threadedinto an ear 65 provided on the bell 59. A: spring 66 having one endconnected to the bell and the other end connected vto the'fan housingurges the bell toward the fan housing so that by adjusting the stopscrew 64 the distance between the bell and the fan inlet can be varied.The fan is driven by a-motor 61 which is mounted on the base plate 60.

The rear .end 'of the air duct 36 has a damper 68 /pivoted therein on across shaft 69. The rear of the casting 30 turns'downwardly, a smallplate being provided at thelower end of the casting to nt around theoutlet 62 of the fan. The damper V68 being back of the inlet 32 for thecoal limits the amount of air that wil1 be delivered from the fanagainst the coal falling from the inlet 32. The shaft 69 ris journaledin the casting 30 and extends outwardly through the casting (see Figure5) and through a bracket 1.! where it is provided with a lever 12.k Thelever 12 can be adjusted to varythe position' of th'e'damper V68 Vand itcan be locked in position by a lock pin 13 which rides in a slot 14 ofthe bracket 1l.

Referring now to the air duct 36 and the hot gas duct 31, it will benoted .from an examination stantially unobstructed from the inlet 32 toa point at where it expands laterally and is divided into two channelsby an adjustable vane 16. This adjustable vane is keyed to a pin 11 thatis journaled in the casting 38 and extends upwardly above it. The pin 11(see Figures 3 and 5) is fixed to a link 18 which in turn is pivoted toa bell crank lever 19 that has a slot 80 in which a pin 8l of the link18 rides. The bell crank lever is pivoted on the casting 39 by apin 82and is connected'to av manually adjustable link 83 which has a handle 84thereon. This link 83 is screw threaded and has two nuts 85 and 86thereon spaced apart so as to receive a Vlug 81 therebetween. The lug81. is slotted to receive the link 83. In normal operation the vane ofFigures 4 and 6 that the air duct 361s sub- 75 16 is Voriginallyadjusted by setting the nuts 85 and 86-so as to-:divide the coal betweenthe two diverging channels in such fashion as to give the properdistribution in the furnace. When it is desired to `cutoff the dischargefrom one side or the other-of the Yfurnace the operator lifts the link83Y by means of the handle 84 and then by pushing orV pulling on thelink 83 he can turn the vane 16 soas to close one of the dischargechannels and ,direct allof the fuel through the other one. Y Y

The operator, by directing all of the fuel to one side of the furnace,can burn out the fuel on the other side and clean the .grate and thenspread the re over bothsides of the grate. I-Ie doesnt have to put outthe fire to clean the grate.

The hot gas inlet conduit 31 (see Figures 2 and 6) has downwardlydirected elongated openings 1 88 lat the front end of the casting.Between the openings there are a series of webs 89 that extend acrossthe passage in the conduit 31. Likewise throughout the length of theconduit 31 there are a plurality of posts 90v connecting the bottom wallof the conduit with the web 38 so as to provide ample means'to deflectthe hot gases and to transmit heat from the gases to the web 38. At itsrear end the duct 31 isv curved around a web 31a so as to baffle the hotgases directly beneath the coal inlet 32 and insure adequate heating ofthe coal receiving part of vthe-.casting 30. The duct 31 opensdownwardly intoythe tube 56. When the bell 59 is over .the inlet 63 ofthe fan it will be obvious that the fan suction will draw hot gasesthrough the inlet openings 88 and through the duct 31, then down throughthe tube 56 and the bell 59 Ato the fan. The suction in the duct 31 willbe governed by the spacingbetween the fan inlet andthe bell 59. A Byadjusting the bell 59 by means of the stop screw 64 the rate of flow ofthe hot gases can be regulated andthe heating of the casting 39 can becontrolled. 1

Owing to the fact that the direct heat from the grate upwardlytoward theinlet openings 88 and the now of hot gases to these openings would tendto burnout the frontend of the duct 31 I provide means-forprotecting theinlet openings 88 in the front end ofthe duct 31. This means comprises ahollow casting 9| (see Figures 2, 6 and 7). The hollow-casting =9| lhasan opening 92 by which the gases may passto-the openings 38. Thiscasting is supported by-a pair of ears-93 and 94 on the casting 30 andby inturned lips 95and 96 on the hollow casting 9i.V f

The discharge .ends 36a and 36h of the conduit 36 are rounded asindicated at 91 and 98 (see Figure '1) so asy to tend to deflect thefuel out# wardly. and downwardly 4at the-front of the furnace. Thisdeflection however is not suicient to take care of the particles thatshoot Straight out the difficultyV of having the coal blown over thebridge wall', and furthermore, in order to protect the discharge ends36a' and 35h of the conduit 36.1

provide a shielding'casting 99 which extends folwardly and .downwardlyover the discharge openings 36a and 36h. This casting is notched aslin'-dicated at Yto receive two ribs |0"|` and |02 that are provided on the.top of the casting at'its forward end, the ribs serving as apivoton--which thercasting 99 may rock. l The casting illl'has arearwardly extending arm |03by which it can be adjusted. `This arm is'extended underneathA the 'long arm |04 `of av bell crank |15,` theshordar'm iofxwhich extends upwardly alongside cfthe casting 30 in frontof a lug |01. An adjusting screwflll is threaded through the lug |01 and'by turning this screw the bell'fcrank lever |05can be rocked on itspivot to raise land lower the end |04 thereof. Obviously if the end |04is depressed the free end of the casting'09 is lifted due to thepressure of the end |04 onithe arm |03. Likewise if it is desired tolower the free end ofthe casting 99 the arm |04 is raised.

In order to inspect the conduit immediately` adjacent the inlet 32 Iprovide an opening |09 in the side of the casting 30. This opening isclosed by a movable plate I0. Of course when it is desired to clean theinterior of the conduit 36 this can be done by simply lremoving thestoker from the furnace so that access Amay be had through the dischargechannelsa and 36h.

Any suitable means may be provided for fastening the stoker in positiononce it has been brought up to a furnace. For this purpose I have showna bracket I (see Figure 2) pivoted on the post 50 and provided with anadjustable link I2. On the end of the link ||2 I provide a hook ||3 andany suitable pin ||4 can be fastened to the furnace front to receive thehook I3.

The arrangement of the feed screw 25 so as to feed coal upwardly to theperforations 35 an'd thus permit the coal to work through theseperforations also enables me to prevent large particles of coal fromgetting into the conduit 36 and clogging it. The housing H5 encloses theupper portion of the screw 25 but this housing is open at its upper endso that any coal which does not pass through the perforations 35 willsimply be fed out of the upper end of the housing and will fall backinto the lower part of the hopper.` An agitator wheel ||6 of a wellknown design has gear teeth ||1 thereon engaging with the feed screw 25to turn the agitator wheel. This agitator wheel is journaled upon ashaft ||8 that extends transversely of the hopper, the wheel beingpositioned by pipe sections IIB interposed between the hub of the wheeland the sides of the hopper.

In order to move the Vcoal inwardly from the sides of the hopper to thefeed screw I secure the pipe sections H9 to the hub ofthe sprocket wheelH6. I mount on the pipe sections two discs |20 and |2| which have wedgeshaped lugs |22 and |23 thereon arranged to push the coal toward thefeed screw as the discs rotate. The discs are fixed to the pipe sectionsIIS which are welded to the hub of the sprocket agitator wheel H6. Thediscs therefore rotate in unison with the sprocket Wheel. The sprocketwheel has pins |24 thereon to agitate the coal.

The feed screw housing ||5 is held in place on the bottom of the hopperby two angle irons |25 and |26 (Fig.' 3) iwhicharefastened tot'hezhop-`perbottom 24:' The housing is cut away as shown ini Figure 2 `at theheightiiindicated at |21 to allow coal to feed into the screwfrom thesides; In order to fill in the bottom of the hopper on oppositesides. ofthe cut away housing up to the'level indicated at `|21 I employ floorboards .(notfshown) `and bevel the upper edges so that the coal 'willnot lodge at that point.` .The lower part of the hopper .oor is`desirably provided with drainopenings |28` so that water from wet coalcandrainout. i -Theshielding'casting 99 is soshaped on "its lower or`coal engaging surfaceas to directfand spread the coalaccording to theneeds of the installation; yAplan'efsurface as shown or asur-A face ofany'cther desired nature may be'lfus'ed; The castingacts to spread thecoal laterally as wellas tojdeect it downwardly.` j l 1' v From theforegoing description it isA believed that the nature and advantages ofthe present invention will' be readily apparent to those skilled in thisart. Y .l i 1 Having thus `described my invention, what I claim las newvand desired to secureby Letters Patent is: 'if f` 1. A stokerof thecharacter "described, "c'omprising a fuel feeding duct, a fan :havingits outlet connected to said'duct whereby to supply `a fluid blast toadvance coal through said duct,` a coal inlet to said Aduct, said ducthaving means at its outlet end to spread coal laterally as it is Y blownfrom the duct,` a damper in said duct between the fan inlet to the ductand the coal inlet to the duct for controlling `the fluid blast andthereby varying Athe distance to which the coa-1 is blown from saidduct, a second duct contiguous to and having a common wall with the coalfeeding duct, said second duct having an inlet at the coal discharge endof the coal feeding duct, and means for connecting the suction side ofsaid fan to the second duct whereby to cause the fan to draw gasesthrough the second duct, from the area adjacent to the discharge end ofthe fuel feeding duct.

2. A stoker of the character described, comprising a fuel feeding duct,a fan having its outlet connected to said duct whereby to supply a fluidblast to advance coal through said duct, a coal inlet to said duct, saidduct having means at its outlet end to spread coal laterally as it isblown from the duct, a second duct contiguous `to and having a commonwall with the coal feeding duct, said second duct having a hot gas inletat the coal discharge end of the coal feeding duct, and means forconnecting the suction side of said fan to the hot gas duct whereby tocause the fan to draw hot gases through the hot gas duct, said secondduct having a baille chamber directly beneath the coal inlet to said rstduct for increasingtheat transfer to the rst duct at the coal inle 3. Astoker of the character described, comprising a fuel feeding duct, a fanhaving its outlet connected to said duct whereby to supply a fluid blastto advance coal through said duct, a coal inlet to said duct, said ducthaving means at its outlet end to spread coal laterally as it is blownfrom the duct, a second duct contiguous to and having a common wall withthe coal feeding duct, said second duct having a hot gas inlet at thecoal discharge end of the coal feeding duct, and means for connectingthe suction side of said fan to the hot gas duct whereby to cause thefan to draw hot gases` through the hot gas duct, said connecting means vincluding. means -to vary the suction effect of theA fan on the hot gasducti'and y thereby Vvary the -ratefof drawing hot *gases through saidduct.- v f 4. A stoker of the character described, corn.-V prising afuel feeding duct, a fan having its outlet connected to said ductwhereby to supply Va fluid blast to advance coal through said duct, acoal inletl to said duct, said duct having-means at its outlet end tospread coalqlaterally as it is blown from the duct, asecondductcontiguous to and having a common wall with the coalffeedingduct, said second ducthavingahnt-gas iinlet 'Y at theA coal dischargeend-of the coal feeding duct, a removable casting. covering the'hot vgasinlet to said second duct-andv supported by said second duct, and meansfor' connecting the suction side of said fan to the hot gas duct wherebytocause the fan to draw hot gases throughthe hot gas duct.

5. A- stoker of the character described comprising a fuel feeding duct,afan having itsout-V let connected t0 said duct whereby to supply4 afluid blast to advance fuel particles'through said duct, a fuel inlet tosaid'duct, s aid duct having means at its outlet end to spread fuelparticles laterally as they areblown from the duct, a second ductcontiguous to said fuel feeding duct, and having a common heat4conducting wall therewith, the second duct having a hot gas inlet at thefuel discharge end of the fuel feeding duct,

ing `casting having one end secured on the frame in position to receivefuel from a hopper or other source, said casting having the other endextending horizontally from the frame a substantial distance forinsertion into a furnace, said casting having two ducts therein, oneduct having an air inlet and a fuel inlet, the other duct having a hotkgas inlet adjacent to the extending end of the first named duct, and adischarge outlet adjacent to the air inlet of the rst named duct, a fan,,thetdischarge outlet of the fan being connected: to the air inlet ofthe first named duct, ,and manually adjustable means for causing the fanto 'draw more or less hot gases through such second .duct for heatingthe casting.

In a Stoker having a main frame, a coal feeding casting having one endsecured on the frame in position to receive fuel from a hopper or othersource, said casting having the other end extending horizontally fromthe frame a substantial distance; for insertioninto a furnace, saidcasting having two ducts therein, one duct having an air inlet and afuel inlet, the other duct having a hot gas inlet adjacent to theextending end of the first named duct; anda discharge outlet adjacentkto the air inlet of the irst named duct, a fan, the discharge outlet ofthe fan being connected tothe air inlet of the first named duct,

Y andmanually adjustable means for causing the and means connecting thesuction side of said fan to the hot gas duct whereby to cause the fan-to draw hot gases through the hot gas duct, and thereby heat the fuelfeeding duct.

6. In a stoker having a main frame, a coal feedfan to draw more or lesshot gases through such second duct for heating the casting, said lastnamed means comprising a conduit forming va part ofthe discharge outletof the second duct, and adjustable toward and away from the fan inlet.

GEORGE A, KOHOUT.

